Mobile neuroimaging has been available for some time. The Danish company Ceretronix has manufactored the Cortexplorer 16 “compact, mobile, 16 detector bedside” brain scanner which seems to have been used since 1992 by researchers. According to the documentation on the Web (on a Web page that hasn’t been updated since 2002) the results are are presented after 15 minutes on a PC. It seems to be a fairly old system (20 years?), but the brain scanner has wheels so it is mobile!

Now my colleagues at the Section for Cognitive Systems at the Technical University of Denmark have constructed a system that employs the Emotive EEG system together with a smartphone for real-time 3D brain mapping. The reasonably priced Emotive EEG system is 14-channel and it has wireless connection to a small USB device. The USB device can be plugged into a smartphone (if you have an adapter between the normal and the small USB stick) and provided you have an appropriate driver for the device you can access the EEG signal from the smartphone. Our Arkadiusz Stopczynski has got a hold on a driver and programmed a Qt application for the Nokia N900 smartphone. It uses OpenGL visualization and touch-based interface so a coarse polygon-based representation of the brain surface can be updated and rotated in real-time smoothly. To colorcode the brain surface based on the EEG signal Stopczynski uses an algorithm by Carsten Stahlhut. Stahlhut studied these kinds of algorithms in his PhD.

There are earlier computer programs that can read EEG signals and present 3D visualization of the brain activity, e.g., on the Emotiv homepage is a commerical Windows application. What is surprising with the system of my colleagues is that they are able to do the colorcoding algorithm (the inversion) on a smartphone. I wouldn’t immediately have thought that a smartphone would have enough computer power to perform this kind of usually quite computational expensive operation. It helps there are few electrodes and that the representation of the brain surface is coarse: There are only 14 EEG channels and around 1’000 vertices in the brain surface model.